This function returns TRUE if the value is a logical value (TRUE or FALSE). Otherwise, it returns FALSE.
Syntax
ISLOGICAL(value)
Arguments
- value (required) – The expression to check (a number, text, a formula without an equal sign, a logical value, an error value, a reference, or a name).
Background
- Part of the IS() function family, which evaluates arguments without conversion (e.g., numeric strings remain text).
- Commonly used with IF() to validate logical conditions before calculations.
- Useful for conditional formatting and data validation rules.
Examples
- Converting Logical Values to Text Messages
Replace TRUE/FALSE with custom messages using nested IF():
=IF(ISLOGICAL(H60), IF(H60, « Correct », « Not correct »), H60)
- If H60 contains TRUE → Returns « Correct »
- If H60 contains FALSE → Returns « Not correct »
- If H60 is non-logical (e.g., text, number) → Returns the original value.
Key Takeaways
- ISLOGICAL() ensures clean handling of logical values in formulas.
- Combine with IF() for user-friendly outputs or conditional formatting for visual cues.
- Avoids errors by explicitly checking for TRUE/FALSE before processing.